Sundays Earth Day electronics recycling in Union Square drew 2,900 people, according to the Department of Sanitation, which organized the event along with the Lower East Side Ecology Center. The dropped-off old electronics  40 tons worth  filled two tractor-trailers. A Sanitation official said 600 people who participated arrived in cars while 2,300 arrived on foot. Several also arrived on bicycles. At left, a pile of old computer monitors waiting to be loaded onto a truck.